How to Repair Projection Distortion in Photoshop

Buildings often look like they are tipping over in street level photographs. Correcting the perspective will fix this.

Because taking a photograph inherently involves translating a three-dimensional image to a two-dimensional plane, projection distortion often occurs. Also called keystone, projection error occurs when the lines in an image that should be parallel slope toward one another. This can be fixed in Photoshop by stretching or contracting the image to make the lines parallel again.

Things You'll Need

• Digital image file
• Computer with at least Photoshop CS2

Instructions

1. Open your image by going to "File," the "Open."

2. Select the crop tool by pressing "C" or selecting it from the tool palette.

3. Draw a crop around the entirety of the image.

4. Click "Perspective" in the top toolbar. This allows you to drag the corners of the crop individually to fix the perspective.

5. Adjust the crop so the lines of the crop box are parallel to the lines you want to fix.

6. Press "Enter" to confirm the crop.

7. Examine your image to make sure the perspective has been corrected fully. If not, undo the crop and try again until you get it right. Eying the perspective takes getting used to, so don't be surprised if getting it right takes longer than you think it should the first few times.

Tips & Warnings

• Because adjusting the perspective degrades the image, do your best to get the perspective correct in camera.

• Images with extremely skewed perspectives might be unrecoverable, as there may not be enough pixels to interpolate from after the crop.

References

• Photoshop Box: Tutorials - Fix Perspective